Vehicle stability operator feedback system

ABSTRACT

System for monitoring vehicle operating conditions and parameters and issuing warnings to the operator when a predetermined vehicle status is present. The predetermined vehicle status includes a variety of unsafe driving conditions and is responsive to a changing center of gravity. The warnings include visual, audible and tactile feedback. By way of the tactile feedback, the system can affect the operator&#39;s operation of the vehicle to prevent vehicle instability, rollover, loss of vehicle control or other unsafe driving conditions from occurring.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a system for monitoring vehicleoperating conditions and parameters and providing feedback to thevehicle's operator indicating potential vehicle instability.

[0003] 2. Description of the Related Art

[0004] Many vehicles, including construction equipment, firefightingvehicles, large trucks and so-called sport-utility vehicles, have highcenters of gravity (C.O.G.'s) This results in decreased stability, anincreased risk of vehicle rollover and/or loss of vehicle control, aswell as other safety-related concerns.

[0005] Further, when loaded with cargo or passengers, the C.O.G, of avehicle will change. The inability of the operator to anticipate avehicle's handling characteristics based upon the changing C.O.G. of avehicle may be largely responsible for many accidents.

[0006] As a result, devices have been devised that measure forces actingon a vehicle and warn the operator when these forces exceed safe levels.In response, the operator can slow the vehicle or widen the turningradius.

[0007] One such device is disclosed in U.S. Pat. No. 6,130,608. Thisdevice measures lateral g-forces or acceleration and sounds an audiblealarm when the g-forces exceed a set threshold. The threshold can beadjusted by the operator.

[0008] As the C.O.G. of the vehicle changes, its ability to remainstable with the presence of changing levels of lateral forces alsochanges. Thus, to be effective, the threshold must be adjusted on suchoccasions as when an unloaded vehicle is loaded with cargo or avehicle's boom is extended or bed raised. Further, fuel consumption andthe resulting emptying of a vehicle's fuel tank will change a vehicle'shandling characteristics.

[0009] However, known devices rely upon the operator to set theappropriate level. In many cases, the operator will be unable toproperly estimate an appropriate threshold, adjust it too high to avoidthe nuisance of the alarm, or neglect to adjust the threshold when thevehicle's load changes.

SUMMARY OF THE INVENTION

[0010] According to an aspect of the present invention, a vehiclecondition operator feedback system is provided. The system comprises avehicle operating condition determining means for determining aplurality of operating conditions, at least one of the plurality ofoperating conditions being affected by a present center of gravity ofthe vehicle. The system further comprises a control means for deducingthe presence of a predetermined vehicle status based upon an operatingcondition signal received from the determining means. The system furthercomprises an operator feedback means for indicating the presence of thepredetermined vehicle status to the operator of the vehicle based upon acontrol signal received from the control means.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a schematic illustration of a vehicle stability operatorfeedback system according to one embodiment of the present invention;and

[0012]FIG. 2 is a schematic illustration of a center of gravity sensorarrangement according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0013]FIG. 1 illustrates the general interconnection of components of anembodiment of the present invention. A vehicle condition operatorfeedback processor, controller or other control means 10 receives aplurality of signals from a vehicle operating condition determiningmeans or apparatus which comprises various sensors 12 mounted in avehicle (not shown). Each of the sensors is capable of measuring aspecific condition related to the operation, configuration or environsof the vehicle. The sensors 12 include measurement or detection ofaccelerations and decelerations (including lateral g-forces), steeringactuator position. wheel angle positions, load characteristics, brakeactuator position, brake fluid pressure, throttle actuator position,engine revolution speed, engine power, engine torque, ground speed,wheels differential speeds, incline, GPS-based or other speed, locationand heading determinations, road transponder information, ambientpavement temperature, pavement friction, and vehicle roll rate.Additional sensors that are known in the art for determining a vehiclecondition can also be used. The term determining as used herein refersto determining, detecting, sensing, measuring, obtaining, acquiring,calculating and the like. Further, “vehicle operating condition” as usedherein includes vehicle conditions, environmental conditions affectingvehicle operation, and the like. Those vehicle conditions listed hereinare intended by way of example only, and other determined conditions canbe used without depart from the intended scope of the present invention.

[0014] There are generally two types of vehicle conditions which can bedetermined by the sensors 12. The first type is determined conditionsthat are largely dependent on the specific characteristic vehicle as itis presently configured, such as vehicle suspension and frame responseto static loading. These conditions are affected by a vehicle's changingC.O.G. Other conditions are largely independent of the vehicle andrelate to the present operation of the vehicle, such as lateralg-forces, velocity, acceleration, inclination and wheel angles. Some ofthe measured conditions may be both vehicle and operation dependent.

[0015] By using a vehicle operating condition signal or input of one ormore of the sensors 12, the processor 10 is capable of deducing when apotentially unsafe driving condition may be present and warning thedriver or operator of the vehicle. As used herein, “predeterminedvehicle status” includes, but is not limited to, a potential for vehicleinstability, a potential for vehicle rollover, a potential for loss ofvehicle control, and any other potentially unsafe driving condition. Theprocessor 10 uses previously gathered or predefined data from a databaseor lookup table 16 related to a specific vehicle having certain variableor changing conditions, including load and C.O.G., various calculationsand algorithms, and other techniques to deduce the presence of thepredetermined vehicle status. Since the vehicle conditions includeconditions that vary with or are affected by the vehicle's presentC.O.G., the operation of the processor 10 is responsive to the changingC.O.G. of the vehicle. Thus, no adjustment of the processor 10 orsensors 12 by the operator is required when the C.O.G. of the vehiclechanges.

[0016] A basic dynamic model of a vehicle from either analysis orexperiment is programmed into the processor 10 to serve as an initialmodel. The processor 10 will then use the basic model to deduce avehicle specific model and then store it as the initial model in thedatabase 16 for this specific vehicle.

[0017] The processor 10 uses knowledge-based algorithms including, butnot limited to, rule-based algorithms, neural network techniques,programmed set-limits and digital signal processing to determine thepresent vehicle condition, including stability as affected by a changingcenter of gravity, in real time and predict the possible vehiclebehavior in the immediate future based on present operating conditions.

[0018] One or more operator feedback means or apparatuses are connectedto the processor 10. When the processor 10 determines that an unsafecondition may be present or is likely to occur, it sends a controlsignal to activate one or more of these feedback means 14. The feedbackmeans 14 include various types of visual and audible alerts, such asbuzzers or flashing lights.

[0019] Another type of feedback means 14 is tactile feedback. One typeof tactile feedback includes providing resistance to a mechanical input,such as the vehicle's steering mechanism or throttle pedal, using knowntechniques. The resistance has the effect of making it more difficultfor the operator to narrow the vehicle's turning radius using thesteering wheel or accelerate using the throttle pedal. In this way, theprocessor 10 communicates to the operator of the vehicle that it may notbe safe to further increase the vehicle's speed or to tighten theturning radius. Other mechanical components of the vehicle could also becontrolled in this way.

[0020] Further, another type of feedback means 14 includes providingpositive force and/or backforce to vehicle controls or mechanicalinputs, such as the vehicle's steering mechanism, brakes or throttleactuator, using known techniques. This force feedback has an effectsimilar to the application of resistance, except that it pushes backwith a force greater than that which was originally applied by theoperator. However, the force exerted is negligible, such that it may beovercome by the operator. The backforce provides operator awareness ofincreasing levels of vehicle instability and prompts the operator tomodify his/her operation of the vehicle's brakes to slow the vehicle.Other mechanical components of the vehicle could also be controlled inthis way vehicle to prevent rollover, such as slowing the vehicle orincreasing turn radius.

[0021] An additional type of feedback is vehicle control override. Thistype of feedback is similar to tactile feedback, and specifically toforce feedback, except that force is applied to the mechanical inputswith a force too great for the operator to reasonably overcome.Alternatively the force may be applied directly to a control mechanismof the vehicle, such as the vehicle's accelerator, steering mechanism orbrakes. Vehicle control override has the effect of modifying the vehicleoperation automatically, without the operator's intervention. Overrideis especially useful when vehicle instability or another conditionbecomes so great that the operator would not have adequate time to reactif prompted by another form of feedback.

[0022] An output of the processor 10 could also be connected to anexisting device that determines the presence of dangerous drivingconditions and alerts the operator, such as that disclosed in U.S. Pat.No. 6,130,608, the entire disclosure of which is incorporated herein byreference. In this case, the processor 10 could be adapted to increaseor decrease the lateral g-force threshold of the device, as appropriatebased upon present vehicle conditions.

[0023] Further, an output of the processor 10 could be connected tocontrol an active or reactive vehicle suspension calibration, adjustmentor setting using known techniques to provide optimum performance orincreased vehicle dynamic stability based upon present conditions.

[0024] The processor 10 has three principal modes of operation: amonitoring mode, a learning mode, and an operating mode. In themonitoring mode, the processor 10 can be used to acquire data from thesensors 12 for different conditions and store the data in the database16 or transmit the data for use by vehicle monitoring computers forsimulation and analysis. The monitoring mode would allow engineers todetermine appropriate limits and formulas for use by the processor inthe operating mode. Additionally, the acquired data could be used tofundamentally improve the configuration of the vehicle.

[0025] In the learning mode, the processor 10 acquires data from thesensors 12 as well as user input to set various operating limits for usein the operating mode. During the learning mode, the engineer performsvarious tests on the vehicle under different operating conditions andindicates to the processor 10 when maximum safe operating conditions arereached or exceeded. Acquired data may be stored in the database orlookup table 16.

[0026] In the operating mode, the processor 10 would acquire and processdata from the sensors 12 related to present operating conditions anddetermine present vehicle stability based upon algorithms and/ordatabase 16 information and control the operator feedback means 14 asappropriate.

[0027] Additional possible operation modes of the processor 10 mayinclude vehicle accident recording, route simulation, routeoptimization, turn-apex detection, steering feedback, and operatortraining.

[0028] It should be evident that this disclosure is by way of exampleand that various changes may be made by adding, modifying or eliminatingdetails without departing from the fair scope of the teaching containedin this disclosure. The invention is therefore not limited to particulardetails of this disclosure except to the extent that the followingclaims are necessarily so limited.

What is claimed is:
 1. A vehicle condition operator feedback systemcomprising: a vehicle operating condition determining apparatus mountedto a vehicle, the determining apparatus determining a plurality ofoperating conditions, at least one of the plurality of operatingconditions being affected by a present center of gravity of the vehicle;a controller which receives an input from the determining apparatus anddeduces the presence of a predetermined vehicle status; and an operatorfeedback apparatus, activated by the controller to indicate the presenceof the predetermined vehicle status to the operator of the vehicle basedupon the input, the feedback apparatus providing at least one form offeedback comprising at least one of an audible warning, a visualwarning, a tactile warning, and vehicle control override.
 2. The systemof claim 1, wherein the controller activates the feedback apparatusbased upon a comparison of the input to predefined data.
 3. The systemof claim 1, wherein the controller activates the feedback apparatusbased upon an algorithm.
 4. The system of claim 1, wherein each of theplurality of operating conditions is selected from acceleration,deceleration, steering actuator position, steering rate, wheel angleposition, load, brake actuator position, brake fluid pressure, throttleactuator position, engine revolution speed, engine power, engine torque,ground speed, driving wheels differential speed, incline, location, roadtransponder information, ambient pavement temperature, pavementfriction, vehicle roll rate, center of gravity and heading.
 5. Thesystem of claim 1, wherein at least one of the plurality of operatingconditions is determined on the basis of information acquired from aglobal positioning system.
 6. A vehicle condition operator feedbacksystem comprising: a vehicle operating condition determining means fordetermining a plurality of operating conditions, at least one of theplurality of operating conditions being affected by a present center ofgravity of the vehicle; a control means for deducing the presence of apredetermined vehicle status based upon an operating condition signalreceived from the determining means; and an operator feedback means forindicating the presence of the predetermined vehicle status to theoperator of the vehicle based upon a control signal received from thecontrol means.
 7. The system of claim 6, wherein the feedback meansprovides at least one form of feedback provided by at least one of anaudible warning means for providing an audible warning, a visual warningmeans for providing a visual warning, a tactile warning means forproviding a tactile warning, and a vehicle control override means foroverriding an operation of a vehicle control mechanism.
 8. The system ofclaim 6, wherein the control signal is based upon a comparison of theoperating condition signal to predefined data.
 9. The system of claim 6,wherein the control means send the control signal based upon analgorithm.
 10. The system of claim 6, wherein the plurality of operatingconditions are selected from acceleration, deceleration, steeringactuator position, steering rate, wheel angle position, load, brakeactuator position, brake fluid pressure, throttle actuator position,engine revolution speed, engine power, engine torque, ground speed,driving wheels differential speed, incline, location, road transponderinformation, ambient pavement temperature, pavement friction, vehicleroll rate, center of gravity and heading.
 11. The system of claim 6,wherein at least one of the plurality of operating conditions isdetermined on the basis of information acquired from a globalpositioning system.
 12. A method for alerting an operator to thepresence of a predetermined vehicle status in a vehicle, comprisingsteps of: determining a plurality of operating conditions of a vehicle,at least one of the plurality of operating conditions being affected bya present center of gravity of the vehicle; deducing the presence ofpredetermined vehicle status based upon the determined plurality ofconditions; and indicating to an operator the presence of thepredetermined vehicle status.
 13. The method of claim 12, wherein thestep of deducing includes a comparison of the input to predefined data.14. The system of claim 12, wherein the step of deducing includes theuse of an algorithm.
 15. The system of claim 12, wherein the pluralityof operating conditions are selected from acceleration, deceleration,steering actuator position, steering Sep. 19, 2001, wheel angleposition, load, brake actuator position, brake fluid pressure, throttleactuator position, engine revolution speed, engine power, engine torque,ground speed, driving wheels differential speed, incline, location, roadtransponder information, ambient pavement temperature, pavementfriction, vehicle roll rate, center of gravity and heading.
 16. Thesystem of claim 12, wherein at least one of the plurality of operatingconditions is determined on the basis of information acquired from aglobal positioning system.